1. Field of the Invention
The present disclosure relates to a method of transmitting and receiving downlink control information and an apparatus thereof. Particularly, the present disclosure relates to a method and apparatus for configuring a user equipment (UE)-specific search space (USS) when a downlink control channel search space is configured for a UE that supports a coverage enhancement operation or a low complexity UE category/type for a machine type communication (MTC) operation.
2. Description of the Prior Art
Machine type communication (MTC) is a type of data communication, which refers to device-to-device communication or thing-to-thing communication (machine to machine communication) in which one or more entities do not necessarily require human interaction. The MTC that does not require human interaction indicates all types of communication schemes that provide communication without human intervention during a communication process.
An MTC UE may be installed in a place that has a poor propagation environment when compared to a typical UE. To enable the MTC UE to operate in the place having a propagation environment that is worse than that of the typical UE, control information and/or data of each physical channel, which is transmitted based on only a single subframe unit, needs to be repeatedly transmitted in a plurality of subframes.
In the case of the MTC UE, a degree of coverage enhancement that is required for each radio channel environment may be different, and the number of repetitive to transmissions, a transmission power, and the like may be set to be different for each of a plurality of coverage enhancement levels in a single cell.
In this instance, when the same UE-specific search space is set for MTC UEs that are located in a single cell and have different coverage enhancement levels, inefficiency in utilizing radio resources may be caused by repetitive transmission or the like, which is a drawback.